io: Allow empty websocket payload

Some browsers send pings/pongs with no payload, so allow empty payloads
instead of closing the connection.

Signed-off-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This commit is contained in:
Brandon Carpenter 2017-09-12 08:21:50 -07:00 committed by Daniel P. Berrange
parent ff1300e626
commit 3a29640e2c

View file

@ -697,44 +697,42 @@ static int qio_channel_websock_decode_payload(QIOChannelWebsock *ioc,
Error **errp)
{
size_t i;
size_t payload_len;
size_t payload_len = 0;
uint32_t *payload32;
if (!ioc->payload_remain) {
error_setg(errp,
"Decoding payload but no bytes of payload remain");
return -1;
if (ioc->payload_remain) {
/* If we aren't at the end of the payload, then drop
* off the last bytes, so we're always multiple of 4
* for purpose of unmasking, except at end of payload
*/
if (ioc->encinput.offset < ioc->payload_remain) {
payload_len = ioc->encinput.offset - (ioc->encinput.offset % 4);
} else {
payload_len = ioc->payload_remain;
}
if (payload_len == 0) {
return QIO_CHANNEL_ERR_BLOCK;
}
ioc->payload_remain -= payload_len;
/* unmask frame */
/* process 1 frame (32 bit op) */
payload32 = (uint32_t *)ioc->encinput.buffer;
for (i = 0; i < payload_len / 4; i++) {
payload32[i] ^= ioc->mask.u;
}
/* process the remaining bytes (if any) */
for (i *= 4; i < payload_len; i++) {
ioc->encinput.buffer[i] ^= ioc->mask.c[i % 4];
}
}
/* If we aren't at the end of the payload, then drop
* off the last bytes, so we're always multiple of 4
* for purpose of unmasking, except at end of payload
*/
if (ioc->encinput.offset < ioc->payload_remain) {
payload_len = ioc->encinput.offset - (ioc->encinput.offset % 4);
} else {
payload_len = ioc->payload_remain;
if (payload_len) {
buffer_reserve(&ioc->rawinput, payload_len);
buffer_append(&ioc->rawinput, ioc->encinput.buffer, payload_len);
buffer_advance(&ioc->encinput, payload_len);
}
if (payload_len == 0) {
return QIO_CHANNEL_ERR_BLOCK;
}
ioc->payload_remain -= payload_len;
/* unmask frame */
/* process 1 frame (32 bit op) */
payload32 = (uint32_t *)ioc->encinput.buffer;
for (i = 0; i < payload_len / 4; i++) {
payload32[i] ^= ioc->mask.u;
}
/* process the remaining bytes (if any) */
for (i *= 4; i < payload_len; i++) {
ioc->encinput.buffer[i] ^= ioc->mask.c[i % 4];
}
buffer_reserve(&ioc->rawinput, payload_len);
buffer_append(&ioc->rawinput, ioc->encinput.buffer, payload_len);
buffer_advance(&ioc->encinput, payload_len);
return 0;
}